One of the electrical problems with numerous buildings has been the use of aluminum conductors and copper conductors in the same electrical system. Typically, an aluminum conductor is connected directly to the copper conductor through a pressure contact. While such an electrical system can work well for a number of years problems can arise as the electrical system ages.
A number of factors are believed to cause the problems of electrical failure and often fires in electrical junctions in an aluminum/copper electrical wiring system. As aluminum has a higher coefficient of thermal expansion than copper it is believed that the relative expansion between copper conductors and aluminum conductors can lead to loosing of the pressure contact between the conductors resulting in increased resistance which generates heat as the electrical current flows through the high resistance junction.
Another factor is that copper oxidizes over time to form a low resistance electrical conductive layer on the surface of the copper conductor while the oxidation of the aluminum does the opposite, namely, forms an oxidation layer of higher electrical resistance on the surface of the aluminum conductor. The increase resistance due to the presence of an aluminum oxidation layer at the junction between the aluminum and copper generates heat as the current passes therethrough. In addition, because of the different current carrying capacities of aluminum conductors and copper conductors the aluminum conductor in a electrical system may be larger than the copper conductor thus enhancing the connection loosing process as the conductors expand and contract in response to changes in temperature. As a result of various factors as well as the aging of the electrical system conditions arise that can cause fires due to presence of a junction of an aluminum conductor and a copper conductor.
The present invention provides an electrical connector for use in joining aluminum and copper conductors that minimize the occurrence of electrical system failure and the resulting fires. The system can quickly retrofitted to an existing system that uses aluminum and copper wires to thereby remove an electrical fire hazard.